Osama Hamdy, M.D., Ph.D.

Osama Hamdy, M.D., Ph.D., is Director of the Obesity Clinic and Assistant Investigator in the Section on Clinical Research at Joslin, and an Instructor in Medicine at Harvard Medical School. He received his medical and doctoral degrees from Mansoura University in Egypt. Dr. Hamdy did his residency in Internal Medicine at Mansoura University Hospital, and his fellowship in Endocrinology, Diabetes and Metabolism at the University of Missouri Hospital and Clinics and Joslin Diabetes Center. Before coming to Boston, he was an Associate Professor of Internal Medicine at Mansoura Faculty of Medicine in Egypt. He is a Fellow of the American College of Endocrinology.

Dr. Hamdy focuses on the effects of lifestyle modification (diet and exercise) on the function of the endothelium (the layer of cells lining blood vessels) in obese individuals with and without type 2 diabetes. Healthy vascular (blood vessel) function is often altered in obesity and diabetes, and marks the early stage of atherosclerosis and coronary artery disease. Dr. Hamdy and colleagues found that obese adults who lost just 7 percent of their weight—the equivalent of 16 pounds in a 220-pound woman—and did moderate-intensity physical activity for six months had significant improvement in endothelial function. This improvement may eventually prevent progression of atherosclerosis, coronary artery disease and the subsequent risk of heart attack and stroke—the leading causes of death in at least 75 percent of patients with type 2 diabetes.

Dr. Hamdy studies the long-term effects of sustained weight loss on endothelial function, distribution of body fat and circulating adipokines (chemicals produced by fat cells that contribute to insulin resistance, atherosclerosis, inflammation, coagulation and coronary artery disease) in obese patients with type 2 diabetes. He also studies the impact of surgical removal of visceral (abdominal or hidden) fat on insulin sensitivity, endothelial function and blood glucose control for obese patients newly diagnosed with type 2 diabetes—an approach that prompts some hope for treatment of type 2 diabetes and insulin resistance.

To develop better strategies for managing obesity and diabetes through lifestyle modifications, Dr. Hamdy plans to investigate the differences between the effects of diet and  exercise on endothelial function as well as the effects of diets that vary in macronutrients ratio (the proportion of carbohydrates, protein and fat). To better identify patients at risk, he will explore the relationships among fat distribution, adipokines, insulin resistance and endothelial function. He also plans to validate a new index that can be used in clinical practice for identifying people who are insulin resistant and at higher risk for type 2 diabetes and cardiovascular complications.

Selected References
Hamdy O, Ledbury S, Mullooly C, et al. Lifestyle modification improves endothelial function in obese subjects with insulin resistance syndrome. Diabetes Care 26:2119-2125, 2003.

Hamdy O, Moussa A, Ledbury S, et al. Effects of weight loss and increased physical activity on insulin and glucose dynamics in obese subjects with insulin resistance syndrome. Diabetes 51(Suppl 2):411, 2002.